1. Field of the Invention
This invention relates to an image processing apparatus for converting an image signal detected by photoelectrically scanning an image original into a density signal, conducting a color processing of the density signal, and then generating a control signal for controlling a light source used for forming a reproduced image.
2. Description of the Prior Art
There have heretofore been known image reproducing apparatuses wherein a density signal obtained by photoelectrically scanning a color image original is subjected to a color processing such as color correction, sharpness enhancement, or gradation conversion, and the light amount emitted by a reproduction light source is controlled on the basis of the color-processed density signal, thereby reproducing an image of a desired quality. In general, in the conventional image reproducing apparatuses, a positive reproduced image is obtained from a positive color original. Recently, however, a need has been felt to obtain an intermediate negative from a positive color original, a positive image from a negative original, or an intermediate negative from a negative original.
However, various problems arise when the signal processing system for obtaining a positive image from a positive original in the conventional image reproducing apparatuses is directly used for forming an intermediate negative from a positive original, a positive image from a negative original, or an intermediate negative from a negative original. For example, in the case where an intermediate negative is formed from a positive original or a negative original and an operator controls various parameters in the color processing step in the same manner as when a positive image is formed from a positive original, the intermediate negative formed thereby is such that, when the intermediate negative is ultimately used for printing on a printing photosensitive material, an image of a desired density cannot be obtained due to a difference in spectral sensitivity between the photosensitive material for the intermediate negative and the ultimate printing photosensitive material, or the like. Therefore, when an image is formed on the photosensitive material for the intermediate negative, the operator must take into consideration the spectral absorbances of the dyes of the photosensitive material for the intermediate negative, the spectral sensitivity of the ultimate printing photosensitive material, the spectral intensity of the light source of the printer, and the like. Thus the burden to the operator increases, and he will be unable to carry out the operation without a certain degree of skill. Further, when the original is a negative and a density signal of the negative image is sent to the color processing section, it is not always possible for the operator to accurately control the parameters no matter how skillful he may be.